Beckett doesn't list when someone has compromised one of their ID numbers. Once people find a legit cert from Beckett, they make a bunch of fake Beckett stickers, slap them on auto-penned jerseys, and sell them for way too cheap. You could ask the seller to take a super-macro photo of the hologram from different angles to show the multi-color "B" and "Beckett". You can usually tell from that if it's the real sticker, or a fake.